Web app shows Firefox icon instead of the site icon when PINNED TO START

This may be a small issue but it's pretty bothering, I do understand that the web app as of now is primarily to be pinned at the taskbar, but would this be done in the start menu in the future? I mainly keep my apps at the start menu for my convenience. Basically the problem here is the shortcut icon, so take this Messenger web app as an example. If I pin this to taskbar, or even make a desktop shortcut, it's showing the correct icon, it's also in the start menu but unpinned. However, when I pin it to the start menu, in the app catalog, it changes to the Firefox icon (for some reason the one on the taskbar sometimes does that as well). I've tried looking into the Properties tab of the shortcut, but apparently it's already set to the Messenger icon, so I'm guessing it's primarily the start menu problem.